A silicone which has polymerizable groups on both ends and a hydrophilic side chain is known from the following Patent Literature 1. It is also known that this silicone is copolymerized with a polymerizable monomer to form hydrophilic contact lenses. The silicone is said to be suitable for medical applications, because it does not have a urethane bond. However, the silicone has a drawback that the conversion of the (meth)acryl groups on the ends of the silicone is not enough and, therefore, the physical properties of the contact lenses obtained vary depending on an amount of the unreacted monomers.    Patent Literature 1: Japanese Patent Publication No. Sho-62-29776/1987